Search found 20 matches

by BG
Fri, 22 May 2009, 20:47
Forum: General EV Discussion
Topic: 2 Speed Gearbox
Replies: 309
Views: 50452

2 Speed Gearbox

Have you thought of getting rid of the rest of the gearbox and just using the lockup torque converter?? It might seem silly at first, but it could solve a bunch of problems. The torque multiplication (3x ?) allows you to do a hill start in a gear which would normally be left for cruising. It would a...
by BG
Wed, 20 May 2009, 01:45
Forum: General EV Discussion
Topic: Electric Beemer
Replies: 144
Views: 15011

Electric Beemer

If you're running the coupling to 5500rpm do you think its worth getting it balanced?
by BG
Tue, 14 Apr 2009, 16:53
Forum: The Lounge
Topic: World Solar Challenge
Replies: 8
Views: 1431

World Solar Challenge

oops - second para is a quote from the organisers.
by BG
Tue, 14 Apr 2009, 16:52
Forum: The Lounge
Topic: World Solar Challenge
Replies: 8
Views: 1431

World Solar Challenge

I've been on the WSC a few times before. What they're up to (particularly with the 'technology class') at the moment is anyone's guess.. The only thing that appears to be set is the entry fee, which has more than doubled to $10,000. We're still not sure what you get for the money. It's proposing lon...
by BG
Fri, 27 Mar 2009, 01:33
Forum: General EV Discussion
Topic: EV run to Canberra.. from Perth?
Replies: 39
Views: 4470

EV run to Canberra.. from Perth?

Hi Ian The numbers you originally posted sound about right. Take a look at this: Desert Rose EV I think John Swenson was suffering ill health and the project had stalled somewhat - If it wasn't completed it must be close! Like a solar car without the extra weight and drag of solar cells.. could be v...
by BG
Thu, 26 Mar 2009, 02:57
Forum: EV Motoring
Topic: EVme $70K
Replies: 48
Views: 12869

EVme $70K

Apologies thinking aloud here! Interesting motor... Not only have they combined PM's (in purple) into a squirrel cage rotor but it also seems they added some saliency as well (as per the discussions I saw somewhere about the revision of the prius motor) It makes sense the V/Hz is about the same for ...
by BG
Wed, 25 Mar 2009, 07:19
Forum: Batteries, charging, management and monitoring
Topic: Cycle Life
Replies: 19
Views: 2357

Cycle Life

Does anyone know what effect storage temp has on LiFe Batteries? I think for standard Li-ions the life decreases significantly above 25 degrees, and storing part charged (ie 40-60% as woody suggested) As far as maximising total energy throughput over the life of a battery, I hear around 40% DOD for ...
by BG
Wed, 25 Mar 2009, 07:10
Forum: Batteries, charging, management and monitoring
Topic: New Lithium quick charge technology...
Replies: 10
Views: 1574

New Lithium quick charge technology...

Hey James, you forgot to mention that whenever the motor is broken (ie a lot) the batteries lose their charge!
by BG
Wed, 25 Mar 2009, 06:45
Forum: Electric motors and controllers
Topic: Vatiable field magnet motor
Replies: 17
Views: 2399

Vatiable field magnet motor

Very cool actuation.. In that example, chances are it would work nearly as well with a higher voltage pack.. Assuming its actually radial flux, the b-field isn't reduced in the remaining (unchanged) airgap, sliding the stator out is just reducing the flux linkage to the stator (coils) which give a l...
by BG
Wed, 25 Mar 2009, 06:23
Forum: General EV Discussion
Topic: 2 Speed Gearbox
Replies: 309
Views: 50452

2 Speed Gearbox

This is something I'm looking into further. Gearboxes are this kind of swings and roundabouts thing.. The cogs cost a fair bit - about $1500 each to get 1-offs made!! The other thing to consider is you still need a differential (unless you have two motors) so the idea of a 'gearmotor' doesn't make a...
by BG
Wed, 25 Mar 2009, 05:52
Forum: The Lounge
Topic: Hydraulic Hybrids
Replies: 3
Views: 920

Hydraulic Hybrids

I think it's possible to construct scenarios where hydraulic traction motors etc. could be beneficial. However, I think it really falls apart when you consider the control side of things. Power electronics advances (generally together with digital control) and high torque density electric motors are...
by BG
Tue, 24 Mar 2009, 00:29
Forum: The Lounge
Topic: Hydraulic Hybrids
Replies: 3
Views: 920

Hydraulic Hybrids

yes, had a small part in an Hybrid Bus project many years ago. Anything specific? It took a looong time to get going, I didn't really see it run.
by BG
Mon, 23 Mar 2009, 23:09
Forum: General EV Discussion
Topic: Fuel Cell Safety
Replies: 19
Views: 1633

Fuel Cell Safety


Sure they weren't testing the ford Exploder Image[/QUOTE]

How many Moles per Gallon do you think they would get??
by BG
Mon, 23 Mar 2009, 23:07
Forum: EV Motoring
Topic: How to power cars: Assessing the Alternatives
Replies: 7
Views: 1385

How to power cars: Assessing the Alternatives

keep in mind the baseline spec was an EV that could drive 500km per charge in order to normalise it for the study. If you take it more realistically and give a 200km range, it gets better.
also see:
http://autospeed.com/cms/A_111205/article.html
by BG
Tue, 10 Mar 2009, 21:14
Forum: General EV Discussion
Topic: Electric Beemer
Replies: 144
Views: 15011

Electric Beemer

Hi James     Just as well you have a mech eng on board. Surely the power factor etc. is a result of inductance at a given frequency. Therefore Power factor is unknown if the frequency is unknown? But, they don't supply a value for the inductance either.    Ps you'd better leave that gearbox alone, b...
by BG
Tue, 10 Mar 2009, 03:51
Forum: General EV Discussion
Topic: E porsche with Analog Ac controller
Replies: 51
Views: 5169

E porsche with Analog Ac controller

I think the AC24LS has about 3x less torque. Also yes, 12,000 rpm continuous makes a fair difference, and it can supply reasonable power right up to this limit. Could possibly run it without oil pumps, but the way to find that out is more expensive than buying the pumps.    The issue is the surface ...
by BG
Fri, 06 Mar 2009, 01:00
Forum: General EV Discussion
Topic: E porsche with Analog Ac controller
Replies: 51
Views: 5169

E porsche with Analog Ac controller

Aha! the solution is lead acids told you so it was just a matter of time ;) Then we can ship ev's wherever we want before being filled with electrolyte on arrival. And there's no storage or calendar life problems in the meantime Lol And then the local scrapyard can send them back to china for recycl...
by BG
Wed, 04 Mar 2009, 18:54
Forum: General EV Discussion
Topic: E porsche with Analog Ac controller
Replies: 51
Views: 5169

E porsche with Analog Ac controller

Tritium_James, I really think you should stay away from those Lithium batteries and stick with the superior lead acids. The Lithiums are terrible - dangerous and unreliable. It sounds like the lead acids have proven themselves to be reliable for the last ten years without any trouble.    I mean you ...